/*
 * Copyright (c) 2023, 2024, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * The Universal Permissive License (UPL), Version 1.0
 *
 * Subject to the condition set forth below, permission is hereby granted to any
 * person obtaining a copy of this software, associated documentation and/or
 * data (collectively the "Software"), free of charge and under any and all
 * copyright rights in the Software, and any and all patent rights owned or
 * freely licensable by each licensor hereunder covering either (i) the
 * unmodified Software as contributed to or provided by such licensor, or (ii)
 * the Larger Works (as defined below), to deal in both
 *
 * (a) the Software, and
 *
 * (b) any piece of software and/or hardware listed in the lrgrwrks.txt file if
 * one is included with the Software each a "Larger Work" to which the Software
 * is contributed by such licensors),
 *
 * without restriction, including without limitation the rights to copy, create
 * derivative works of, display, perform, and distribute the Software and make,
 * use, sell, offer for sale, import, export, have made, and have sold the
 * Software and the Larger Work(s), and to sublicense the foregoing rights on
 * either these or other terms.
 *
 * This license is subject to the following condition:
 *
 * The above copyright notice and either this complete permission notice or at a
 * minimum a reference to the UPL must be included in all copies or substantial
 * portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
package com.oracle.truffle.dsl.processor.bytecode.generator;

import java.util.ArrayList;
import java.util.Collection;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.function.BiConsumer;

import com.oracle.truffle.dsl.processor.java.model.CodeTree;
import com.oracle.truffle.dsl.processor.java.model.CodeTreeBuilder;
import com.oracle.truffle.dsl.processor.java.model.CodeElement.StringBuilderCodeWriter;

/**
 * Utility to group values by their produced code. This allows e.g. to group switch statements
 * without complex grouping logic.
 */
public final class EqualityCodeTree {
    private final CodeTree tree;
    private final String source;

    private EqualityCodeTree(CodeTree tree) {
        this.tree = tree;
        StringBuilderCodeWriter codeWriter = new StringBuilderCodeWriter();
        codeWriter.visitTree(tree, null, null);
        source = codeWriter.getString();
    }

    public CodeTree getTree() {
        return tree;
    }

    @Override
    public int hashCode() {
        return Objects.hash(source);
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj) {
            return true;
        } else if (obj == null) {
            return false;
        } else if (getClass() != obj.getClass()) {
            return false;
        } else {
            EqualityCodeTree other = (EqualityCodeTree) obj;
            return Objects.equals(source, other.source);
        }
    }

    public static <T> Map<EqualityCodeTree, List<T>> group(CodeTreeBuilder parent, Collection<T> values, BiConsumer<T, CodeTreeBuilder> grouper) {
        final Map<EqualityCodeTree, List<T>> grouping = new LinkedHashMap<>();
        for (T value : values) {
            CodeTreeBuilder b = parent.create();
            grouper.accept(value, b);
            grouping.computeIfAbsent(new EqualityCodeTree(b.build()), (k) -> new ArrayList<>()).add(value);
        }
        return grouping;
    }
}
